This invention relates generally to a dental shade selector for matching the color of the porcelain veneer of the artificial or prepared tooth or bridgework with the patient's natural teeth, and more specifically relates to a color shade selector and method which more accurately matches the color of the prepared tooth with the adjacent real teeth.
Dental bridgework or crowns generally comprise a rigid supporting frame of a suitable material such as a gold or other alloy on which a porcelain material is fused. The proper color or shade for the porcelain is essential for simulating the prepared tooth with the patient's real teeth. In selecting the correct color for the prepared tooth, the dentist commonly utilizes a color shade guide which includes a plurality of color samples to provide graduating shade variations, for approximating the color match. Generally, these prior guides did not have a metal backing nor did they have similar thickness for the porcelain veneer as the constructed crown or bridge. Therefore, when the selected material from the guide samples originally resembling the natural teeth, was applied to the artificial tooth or bridgework, there was a noticeable variance of color between the completed prepared tooth and the natural teeth.
Some previously disclosed color selectors comprised samples of teeth having a metal or plastic base and a veneer of porcelain. The metal or plastic backing of these samples were not similar in color to the supporting structure of the artificial tooth, and consequently, an accurate reproducible match was not achieved.
The previously used dental color samples did not vary in the thickness of the porcelain veneer spread over or affixed on the body of the sample. Therefore, although the selected color or shade may have been accurate for the outer end of a front tooth, for example, it quite often would be in variance with adjacent teeth in the area of the tooth near the gum line.
In using the prior shade guides, the dentist selected the sample that most closely resembled the color or shade of the teeth adjacent to the fabricated crown. Then the bridgework or crown was constructed using the same porcelain substance for the outer veneer as the selected sample. Usually, the previously used shade guide selectors were provided by a manufacturer. Frequently, the color shade of the fabricated tooth was appreciably different from the selected sample, and consequently, such prior shade guides were not capable of providing reproducible accurate shade variations, eventhough the matching may have been accurate with the selected samples.
The aforedescribed undesirable effect is primarily attributable to the color shade differences between batches of the same color shade compound. Thus, a color difference existed between the color samples and the batch used by the dental laboratory to simulate the artificial tooth with the sample. The color differences have been found to be even more severe when the sample for the shade guide selector is constructed by one manufacturer and the corresponding color shade compound used to simulate the selected sample is provided by another manufacturer.
Furthermore, the dental laboratory may not even have the compound available for matching the dentist's selected sample from another manufacturer's shade guide. In this situation, the dental laboratory would be required to derive the proper shade compound by mixing the constituent parts of the compound and try-fire the compound. Generally, preliminary tooth constructions would be necessary before obtaining even a minimal acceptable color match of the dentist's shade selection.
The dentist in his effort to customize or precisely match the selected sample with the patient's real teeth, may often apply a stain to the selected sample. Since the porcelain veneer of the sample didn't match with the corresponding porcelain compound used for simulating the sample, the stain applied by the dentist further complicated the matching procedure. The subject invention, on the other hand, enables the dental laboratory to easily and accurately customize the staining requirements of the dentist, and precisely reproduce the desired shading on the artificial tooth.
It is, therefore, a primary object of the subject invention to provide a shade selector for accurately matching the fabricated bridgework with the patient's adjacent real teeth.
It is another primary object to provide a method for accurately matching the fabricated bridgework with real teeth.
Another object is to provide a shade selector comprising a plurality of samples corresponding to a graduation of color variations and a detachable handle which is easy to manipulate, for positioning the individual tooth samples in the mouth to select the closest sample to the shade of the real adjacent teeth.
A primary feature of the invention is to use material from the same batch of the material to form the color shade tooth sample and also to form the color simulated artificial tooth.
Another primary feature is to provide a color tooth sample having a frame constructed to approximate the average amount of porcelain reduction during baking, so as to provide an average build up of porcelain, to simulate the thickness for the final restoration.
Another feature is to provide color tooth samples, for varying the color shades both at the outer end of the tooth and adjacent the gum line.
Another feature of the subject invention is to provide a backing, which is constructed from one of the actual metals used as understructure in the production of crowns and bridges.
Still another feature is that the dentist is provided with a tooth button sample which can be stained by him, to customize the shade selection; and, thereafter, the stain can be removed and the tooth button may again be used. (The stain the dentist uses is communicated to the dental laboratory, and easily and exactly reproduced and baked or fired to the porcelain.)